Lukasz Skrzypczak

56f8013 and parallel JTAG interface problem

Discussion created by Lukasz Skrzypczak on Sep 11, 2007
Latest reply on Sep 13, 2007 by Pascal Irrle
I have a strange (and irritating) problem. I have a circuit with 56f8013 on it programmed via JTAG interface plugged into parallel port to PC (AXIOM taken from DEMO56F8013). Until last saturday evening everything was absolutely perfect. Basically what happened is that i get css error: cable not connected. I thought that accidentially i fried DSC but when i soldered another (new) one nothing cjhanged. Stranger thing is that the same JTAG interface works without any problem with demo bord from freescale.
I triple-checked the circuit to find anything wrong and it looks like everything is OK.
Please - help me or i'll loose the last hair on my head ...
Especially - can someone check how does the TMS signal look when JTAG transmision starts over lpt-connected JTAG. Mine generates a few very short and irregular pulses.

thanks in advice
Luke (Warsaw University of Technology)